CVE WatchAug 18, 2026

CVE-2026-45123

MyBB is free and open source forum software. Prior to 1.8.40, the remote requests feature does not correctly handle IPv6 addresses, resultin

CVSS

4.3

Medium

EPSS

0.3%

p19

KEV

—

Exploit Today

0-100

Published: Aug 18, 2026 · Last modified: Aug 18, 2026 · CWE-918

EPSS · 30d

0.3%EPSS · 30 days0.3%

2026-08-192026-08-31

Technical description

MyBB is free and open source forum software. Prior to 1.8.40, the remote requests feature does not correctly handle IPv6 addresses, resulting in a server-side request forgery vulnerability. The default disallowed remote hosts list does not include IPv6 addresses. Verification in fetch_remote_file() fails open when get_ip_by_hostname() returns no result because that function does not return IPv6 results, allowing a crafted remote target to bypass the host restriction. The uniquely identifying implementation details include fail-open verification, and inc/functions.php. This issue is fixed in version 1.8.40.

Official references

Related CVEs

CVECVSSEPSSKEVRExploitTitleMod.

CVE-2026-846975.3 MED

—

———Mailpit's IsInternalIP deny list function fails to block the Azure WireServer address 168.63.129.16 and the RFC 2765/6145 IPv4-translated IPv6 prefix, allowing server-side request forgery to internal destinations. Attackers can supply hostnames resolving to these addresses in message content to reach the link check API and proxy endpoint for accessing internal resources.9h CVE-2026-83548—

—

———A Pre-authentication SSRF vulnerability exists in the SMA1000 Appliance Work Place interface due to an unintended alternate access path. A remote unauthenticated attacker could potentially exploit this vulnerability to gain unauthorized access to sensitive functionality and perform unauthorized operations.6h CVE-2026-76851—

—

———A Server-Side Request Forgery (SSRF) vulnerability was identified in GitHub Enterprise Server that allowed remote code execution on the instance. Insufficient network isolation allowed malicious pre-receive hook code to impersonate an internal service and redirect trusted internal requests to a privileged service, leading to elevated code execution. Exploitation required pre-receive hook networking to be enabled and either site administrator privileges or write access to a repository containing a configured pre-receive hook. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.22 and was fixed in versions 3.17.20, 3.18.14, 3.19.11, 3.20.7, and 3.21.5. This vulnerability was reported via the GitHub Bug Bounty program.12h CVE-2026-18730—

—

———A server-side request forgery (SSRF) vulnerability was identified in GitHub Enterprise Server that allowed an unauthenticated attacker to cause the Manage API to send crafted outbound requests to an attacker-controlled host. An unauthenticated endpoint parsed an attacker-supplied cluster configuration and issued gateway-to-agent requests whose HMAC authenticated only a timestamp, not the request path or body. An attacker positioned to intercept the outbound request could capture this token and replay it against privileged management agent endpoints. High-availability deployments were not affected due to a topology restriction. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.22 and was fixed in versions 3.17.19, 3.18.13, 3.19.10, 3.20.6, and 3.21.4. This vulnerability was reported via the GitHub Bug Bounty program.12h CVE-2026-87128.3 HIG

—

———Wyoming before 1.10.2 contains a server-side request forgery vulnerability that allows unauthenticated attackers with network access to force outbound connections to arbitrary targets by supplying a malicious `uri` query parameter to the HTTP API. Attackers can pass arbitrary `tcp://` or `unix://` URIs to affected endpoints including /api/info, /api/speech-to-text, and /api/text-to-speech to override the server-configured backend and redirect connections to attacker-chosen hosts.15h CVE-2026-842075.4 MED

—

———Heym before 0.0.98 fails to apply SSRF egress guards to WebSocket Send and WebSocket Trigger nodes, allowing authenticated users to connect to internal services. Attackers can craft workflow nodes with arbitrary URLs and headers to reach internal services and read responses from the WebSocket Trigger node.16h